diff --git a/Source/SocketAckEmitter.swift b/Source/SocketAckEmitter.swift
index 6b86460..4af43e7 100644
--- a/Source/SocketAckEmitter.swift
+++ b/Source/SocketAckEmitter.swift
@@ -27,6 +27,10 @@ import Foundation
 public final class SocketAckEmitter : NSObject {
     let socket: SocketIOClient
     let ackNum: Int
+
+    public var expected: Bool {
+        return ackNum != -1
+    }
     
     init(socket: SocketIOClient, ackNum: Int) {
         self.socket = socket
@@ -44,6 +48,7 @@ public final class SocketAckEmitter : NSObject {
         
         socket.emitAck(ackNum, with: items)
     }
+        
 }
 
 public final class OnAckCallback : NSObject {